This letter tackles whether and how repetition coding enables reliable and covert communications by considering binary phase shift keying. Communication reliability and covertness are analyzed in terms of the bit error rate $P_{e}$ and the minimum detection error probability $\xi ^{\ast }$ . Our examination shows that, when a warden Willie knows the codeword structure, both $P_{e}$ and $\xi ^{\ast }$ are determined by the total power nP and do not depend on the codeword length ${n}$ or the transmit power ${P}$ individually. However, this conclusion does not hold for the unknown codeword structure, where increasing ${n}$ can significantly improve the communication reliability under the same covertness constraint, and vice versa.

中文翻译：

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重复编码如何实现可靠和隐蔽的通信？

这封信通过考虑二进制相移键控来解决重复编码是否以及如何实现可靠和隐蔽的通信。根据误码率分析通信的可靠性和隐蔽性 $ P_ {e} $ 和最小检测错误概率 $ \ xi ^ {\ ast} $ 。我们的检查表明，当看守威利知道代码字结构时， $ P_ {e} $ 和 $ \ xi ^ {\ ast} $ 由总功率决定 P 并且不依赖于码字长度 $ {n} $ 或发射功率 $ {P} $ 个别地。但是，该结论不适用于未知的码字结构，在这种情况下， $ {n} $ 可以在相同的隐蔽性约束下显着提高通信可靠性，反之亦然。